Me for 15 years of tendonitis: "I wish I could build arm muscle. It's the best way to support my tendons. But I can't figure out how to exercise without aggravating the injury."
Me after 1.5 years of hefting a 95th-percentile-weight baby: "Wow, I have biceps!"
Last year's round of OT really helped me heal to the point where I could work out, and this year I have my magical Mueller elbow braces, which have let me knit and do housework and type a lot and pick up the baby without being in pain. (I did have a bit of a problem where they were offloading onto my wrists, but my Handeze gloves took care of that.) But I don't think the braces are the only reason I've healed a lot faster from the latest flare-up than ever before. I think I've just plain got more muscle. The braces have a strap that goes around the bicep and another that goes around the meatiest part of the forearm, and I was a little startled the first time I put them on and realized that flexing my bicep made a real difference to the fit. Over the winter I fell out of the habit of doing daily exercises, so I probably haven't strengthened the parts of my arm that most need it, but picking up a wriggly 25-pound toddler every day has definitely done me some good. I don't look quite like the stock photo in my icon, but I look more like it than I used to. One of these days I could even replace that icon with a photo of my actual arm.
I'm still going to the arm doctor next week and asking for a prescription for another round of OT, because when I take off the braces and gloves, I hurt, and I would rather not need assistive devices to do everyday things. Also the wrist pain is a new thing and I definitely want to get that checked out and mitigated before it gets worse. But injury notwithstanding, I feel strong in ways that I haven't in nearly 20 years, and it's pretty great.